SCIENTISTS: cyclones and man-made climate change

This is a compendium of recent scientist and science-informed views
about the connection between man-made global warming and increased
cyclone (hurricane) intensity.

As
will become apparent from the quotations below, there have been
different views at the cutting edge of research in this area of science
(as is normal in science) but a recent international consensus has
been established as set out in item #1 (Knutson et al, 2010):
“Whether the characteristics of tropical cyclones have changed or will
change in a warming climate — and if so, how — has been the subject of
considerable investigation, often with conflicting results. Large
amplitude fluctuations in the frequency and intensity of tropical
cyclones greatly complicate both the detection of long-term trends and
their attribution to rising levels of atmospheric greenhouse gases.
Trend detection is further impeded by substantial limitations in the
availability and quality of global historical records of tropical
cyclones. Therefore, it remains uncertain whether past changes in
tropical cyclone activity have exceeded the variability expected from
natural causes. However, future projections based on theory and
high-resolution dynamical models consistently indicate that greenhouse
warming will cause the globally averaged intensity of tropical cyclones
to shift towards stronger storms, with intensity increases of 2–11% by
2100. Existing modelling studies also consistently project decreases in
the globally averaged frequency of tropical cyclones, by 6–34%. Balanced
against this, higher resolution modelling studies typically project
substantial increases in the frequency of the most intense cyclones, and
increases of the order of 20% in the precipitation rate within 100 km
of the storm centre. For all cyclone parameters, projected changes for
individual basins show large variations between different modelling
studies.”

2. Climate change, MSNBC, commenting on Knutson et al (2010) (item #1):
“Top researchers now agree that the world is likely to get stronger but
fewer hurricanes in the future because of global warming, seeming to
settle a scientific debate on the subject. But they say there's not
enough evidence yet to tell whether that effect has already begun. Since
just before Hurricane Katrina hit Louisiana and Mississippi in 2005,
dueling scientific papers have clashed about whether global warming is
worsening hurricanes and will do so in the future. The new study seems
to split the difference. A special World Meteorological Organization
panel of 10 experts in both hurricanes and climate change — including
leading scientists from both sides — came up with a consensus, which is
published online Sunday in the journal Nature Geoscience… The study
offers projections for tropical cyclones worldwide by the end of this
century, and some experts said the bad news outweighs the good. Overall
strength of storms as measured in wind speed would rise by 2 to 11
percent, but there would be between 6 and 34 percent fewer storms in
number. Essentially, there would be fewer weak and moderate storms and
more of the big damaging ones, which also are projected to be stronger
due to warming… An 11 percent increase in wind speed translates to
roughly a 60 percent increase in damage… The storms also would carry
more rain, another indicator of damage… study suggests category 4 and 5
Atlantic hurricanes — those with winds more than 130 mph — would nearly
double by the end of the century.” [2].

3. Greg Holland ( National Center for Atmospheric Research in Colorado) and Peter Webster (Georgia
Institute of Technology)(2007): “We find that long-period variations in
tropical cyclone and hurricane frequency over the past century in the
North Atlantic Ocean have occurred as three relatively stable regimes
separated by sharp transitions. Each regime has seen 50% more cyclones
and hurricanes than the previous regime and is associated with a
distinct range of sea surface temperatures (SSTs) in the eastern
Atlantic Ocean. Overall, there appears to have been a substantial
100-year trend leading to related increases of over 0.7°C in SST and
over 100% in tropical cyclone and hurricane numbers. It is concluded
that the overall trend in SSTs, and tropical cyclone and hurricane
numbers is substantially influenced by greenhouse warming. Superimposed
on the evolving tropical cyclone and hurricane climatology is a
completely independent oscillation manifested in the proportions of
tropical cyclones that become major and minor hurricanes. This
characteristic has no distinguishable net trend and appears to be
associated with concomitant variations in the proportion of equatorial
and higher latitude hurricane developments, perhaps arising from
internal oscillations of the climate system. The period of enhanced
major hurricane activity during 1945–1964 is consistent with a peak
period in major hurricane proportions.” [3].

4. US Today, commenting on Holland and Webster (2007) (item #3) [with
a graph of number of North Atlantic hurricanes per year versus time
from 1850 to 2007]): “The number of hurricanes that develop each year
has more than doubled over the past century, an increase tied to global
warming, according to a study released Sunday."We're seeing a quite
substantial increase in hurricanes over the last century, very closely
related to increases in sea-surface temperatures in the tropical
Atlantic Ocean," says study author Greg Holland of the National Center
for Atmospheric Research in Colorado. Working with hurricane researcher
Peter Webster of Georgia Institute of Technology, Holland looked at sea
records from 1855 to 2005 in a study published in the British journal Philosophical Transactions of the Royal Society A.
The researchers found that average hurricane numbers jumped sharply
during the 20th century, from 3.5 per year in the first 30 years to 8.4
in the earliest years of the 21st century. Over that time, Atlantic
Ocean surface temperatures increased .65 degrees, which experts call a
significant increase… The new study drew criticism from experts who
dispute the merits of combining data from the late 19th and early 20th
centuries, when hurricane-tracking satellites didn't exist, with
statistics gleaned from more modern technology.” [4].

5. Dr Andrew Ash (director, CSIRO’s Climate Adaptation Flagship) re climate change, floods and cyclones (2011): “We
have had stronger cyclones in history and we have had cyclones just as
large in size, but it is rare to get both a very large and intense
cyclone. The flooding we have experienced to date on the whole has been
within the bounds of historical events though in some areas, such as the
Western Downs in Queensland and parts of Victoria, all time records
have been broken. While extreme events like flooding and cyclones are an
expected feature of La Nina events, the oceans around eastern and
northern Australia are particularly warm at present. It is usual for the
ocean in the Western Pacific to be warm during a La Nina event but the
ocean temperatures are currently the highest on record…[In December 2010
the Southern Oscillation Index, a measure of the extent of La Nina,
recorded a level of 27.1... the highest recorded December value in
history] … The record warm temperatures are most likely a combination of
La Nina and additional warming from human activities. While the
flooding events and cyclones experienced this year aren't caused by
climate change, the record warm ocean temperatures provide conditions
more conducive to exacerbating these naturally occurring events
associated with La Nina." [5].

6. Professor Tim Flannery (mammalogist,
palaeontologist, environmentalist and 2007 Australian of the Year) re
climate change, floods and cyclones (2011): “The individual severe
weather events you point to are the kind of thing climate modelling
predicts will become more frequent as greenhouse gas concentrations
increase.” [5].

7. Australian Bureau of Meteorology (2006) re Tropical cyclones and climate change: “Leading
scientists provide an expert view of the current state of knowledge.
They note that there has been a high level of interest in the topic and
that substantial debate is still occurring within the scientific
community. With regard to the recent tropical cyclone seasons they
conclude: "No single high impact tropical cyclone event of 2004 and 2005
can be directly attributed to global warming, though there may be an
impact on the group as a whole.” Dr Geoff Love, the Australian
Director of Meteorology, has submitted to the World Meteorological
Organization's Commission for Atmospheric Sciences, meeting in Cape
Town, South Africa, a "Statement on Tropical Cyclones and Climate
Change". The Statement was prepared by an expert group of scientists
comprising Dr John McBride and Dr Jeff Kepert of the Bureau of
Meteorology in Australia, Professor Johnny Chan of China, Julian Heming
of the UK, and Dr Greg Holland, Professor Kerry Emanuel, Thomas Knutson,
Dr Hugh Willoughby and Dr Chris Landsea of the US. The paper reaffirms
the finding of a 1998 study saying that any change in the frequency
of tropical cyclones (hurricanes/typhoons) due to climate change cannot
be determined due to a lack of knowledge and limitations of the
available observing technologies. The little evidence that does exist
indicates little or no change in global frequency. It also says that
while some recent studies have suggested the intensity of
tropical cyclones (hurricanes/typhoons) has increased substantially over
the past 50 years due to climate change, the scientific community is
"deeply divided". Some researchers believe the climate record is too
inconsistent to draw such a conclusion due to changes in observations
equipment and methods over time. The panel says it cannot come to a
definitive conclusion in this "hotly debated area"… No single disaster
caused by a tropical cyclone (hurricane/typhoon) in 2004 or 2005 -
including Hurricane Katrina in the US - can be directly attributed to
global warming. Rather, climate change may have an impact on the group
as a whole. Further research is needed.” [6, 7].

8.
Dr John McBride and Dr Jeff Kepert ( Bureau of Meteorology in
Australia), Professor Johnny Chan (China), Julian Heming (UK), and Dr
Greg Holland, Professor Kerry Emanuel, Thomas Knutson, Dr Hugh
Willoughby and Dr Chris Landsea (US), “Statement on Tropical Cyclones
and Climate Change" (2006): “No single high impact
tropical cyclone event of 2004 and 2005 can be directly attributed to
global warming, though there may be an impact on the group as a whole;
Emanuel (2005) has produced evidence for a substantial increase in the
power of tropical cyclones (denoted by the integral of the cube of the
maximum winds over time) over the last 50 years. This result is supported by the findings of Webster et al (2005)
that there has been a substantial global increase (nearly 100%) in the
proportion of the most severe tropical cyclones (category 4 and 5
on the Saffir-Simpson scale), from the period from 1970 to 10995, which
has been accompanied by a similar decrease in weaker systems. The
research community is deeply divided over whether the results of these
studies are due, at least in part, to problems in the tropical cyclone
data base. Precisely, the historical record of tropical cyclone tracks
and intensities is a product of real-time operations. Thus its accuracy
and completeness changes continuously through the record as a result of
the continuous changes and improvements in data density and quality,
changes in satellite remote sensing retrieval and dissemination, and
changes in training. In particular a step-function change in
methodologies for determination of satellite intensity occurred with
introduction of geosynchronous satellites in the mid to late 1970s. The
division of the community on the Webster et al and Emanuel papers is not
as to whether Global warming can cause a trend in tropical cyclone
intensities. Rather it is on whether such a signal can be can be detected in the historical data base.” [6, 7, 8].

9. Quirin Schiermeier (writer for Nature, cartographer, graduate
in geography, statistics and economics from the University of Munich)
on global warming and hurricane intensity (2008): “As this year's
Atlantic hurricane season becomes ever more violent, scientists have
come up with the firmest evidence so far that global warming will
significantly increase the intensity of the most extreme storms
worldwide. The maximum wind speeds of the strongest tropical cyclones
have increased significantly since 1981, according to research published
in Nature this week [see #]. And the upward
trend, thought to be driven by rising ocean temperatures, is unlikely to
stop at any time soon… One of the most contentious issues in the
climate-change debate has been whether the strength, number and duration
of tropical cyclones will increase in a warmer world. Basic physics and
modelling studies do suggest that tropical storms will become more
intense, because warmer oceans provide more energy that can be converted
into cyclone wind. But others believe that atmospheric changes might
have an inhibiting role. Increasing shearing winds - another predicted
consequence of global warming - are thought to suppress the cyclonic
rotation of the storms, for example… The team statistically analysed
satellite-derived data of cyclone wind speeds. Although there was hardly
any increase in the average number or intensity of all storms, the team
found a significant shift in distribution towards stronger storms that
wreak the greatest havoc. This meant that, overall, there were more
storms with a maximum wind speed exceeding 210 kilometres per hour
(category 4 and 5 storms on the Saffir–Simpson scale). Rising ocean
temperatures are thought to be the main cause of the observed shift. The
team calculates that a 1 ºC increase in sea-surface temperatures would
result in a 31% increase in the global frequency of category 4 and 5
storms per year: from 13 of those storms to 17. Since 1970, the tropical
oceans have warmed on average by around 0.5 ºC. Computer models suggest
they may warm by a further 2 ºC by 2100.” [9].

10. Elsner, J., Kossin, J. P. & Jagger, T. H. on global warming and increased tropical cyclone intensity (2008):
“Atlantic tropical cyclones are getting stronger on average, with a
30-year trend that has been related to an increase in ocean temperatures
over the Atlantic Ocean and elsewhere. Over the rest of the tropics,
however, possible trends in tropical cyclone intensity are less obvious,
owing to the unreliability and incompleteness of the observational
record and to a restricted focus, in previous trend analyses, on changes
in average intensity. Here we overcome these two limitations by
examining trends in the upper quantiles of per-cyclone maximum wind
speeds (that is, the maximum intensities that cyclones achieve during
their lifetimes), estimated from homogeneous data derived from an
archive of satellite records. We find significant upward trends for wind
speed quantiles above the 70th percentile, with trends as high as
0.3±0.09ms-1yr-1 (s.e.) for the strongest
cyclones. We note separate upward trends in the estimated
lifetime-maximum wind speeds of the very strongest tropical cyclones
(99th percentile) over each ocean basin, with the largest increase at
this quantile occurring over the North Atlantic, although not all basins
show statistically significant increases. Our results are qualitatively
consistent with the hypothesis that as the seas warm, the ocean has
more energy to convert to tropical cyclone wind.” [10].

11. Mark A. Saunders and Adam S. Lea
(Benfield UCL Hazard Research Centre, Department of Space and Climate
Physics, University College London, Holmbury St Mary, Dorking, Surrey
RH5 6NT, UK) on sea surface warming and increased Atlantic hurricane
activity (2009): “Atlantic hurricane activity has increased
significantly since 1995, but the underlying causes of this increase
remain uncertain. It is widely thought that rising Atlantic sea surface
temperatures have had a role in this16, 17,
but the magnitude of this contribution is not known. Here we quantify
this contribution for storms that formed in the tropical North Atlantic,
Caribbean Sea and Gulf of Mexico; these regions together account for
most of the hurricanes that make landfall in the United States. We show
that a statistical model based on two environmental variables—local sea
surface temperature and an atmospheric wind field—can replicate a large
proportion of the variance in tropical Atlantic hurricane frequency and
activity between 1965 and 2005. We then remove the influence of the
atmospheric wind field to assess the contribution of sea surface
temperature. Our results indicate that the sensitivity of tropical
Atlantic hurricane activity to August–September sea surface temperature
over the period we consider is such that a 0.5°C increase in sea surface
temperature is associated with a ~40% increase in hurricane frequency
and activity. The results also indicate that local sea surface warming
was responsible for ~40% of the increase in hurricane activity relative
to the 1950–2000 average between 1996 and 2005. Our analysis does not
identify whether warming induced by greenhouse gases contributed to the
increase in hurricane activity, but the ability of climate models to
reproduce the observed relationship between hurricanes and sea surface
temperature will serve as a useful means of assessing whether they are
likely to provide reliable projections of future changes in Atlantic
hurricane activity.” [11].

12. Webster, P. J., Holland, G. J., Curry, J. A. & Chang, H.-R. on
changes in tropical cyclone number, duration, and intensity in a
warming environment (2005): “We examined the number of tropical cyclones
and cyclone days as well as tropical cyclone intensity over the past 35
years, in an environment of increasing sea surface temperature. A large
increase was seen in the number and proportion of hurricanes reaching
categories 4 and 5. The largest increase occurred in the North Pacific,
Indian, and Southwest Pacific Oceans, and the smallest percentage
increase occurred in the North Atlantic Ocean. These increases have
taken place while the number of cyclones and cyclone days has decreased
in all basins except the North Atlantic during the past decade… We
conclude that global data indicate a 30-year trend toward more frequent
and intense hurricanes, corroborated by the results of the recent
regional assessment. This trend is not inconsistent with recent climate
model simulations that a doubling of CO2 may increase the
frequency of the most intense cyclones, although attribution of the
30-year trends to global warming would require a longer global data
record and, especially, a deeper understanding of the role of hurricanes
in the general circulation of the atmosphere and ocean, even in the
present climate state.” [12].

13. Professor Kerry Emanuel (Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA) on
warming and increased cyclone intensity (2005): “Theory and modelling
predict that hurricane intensity should increase with increasing global
mean temperatures, but work on the detection of trends in hurricane
activity has focused mostly on their frequency and shows no trend. Here I
define an index of the potential destructiveness of hurricanes based on
the total dissipation of power, integrated over the lifetime of the
cyclone, and show that this index has increased markedly since the
mid-1970s. This trend is due to both longer storm lifetimes and greater
storm intensities. I find that the record of net hurricane power
dissipation is highly correlated with tropical sea surface temperature,
reflecting well-documented climate signals, including multi-decadal
oscillations in the North Atlantic and North Pacific, and global
warming. My results suggest that future warming may lead to an upward
trend in tropical cyclone destructive potential, and—taking into account
an increasing coastal population—a substantial increase in
hurricane-related losses in the twenty-first century.” [13].

14. Professor Kerry Emanuel, Ragoth Sundararajan, and John Williams (Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Cambridge, Massachusetts}on
modeling showing cyclone storm intensity generally increases with
global warming (2008): “Changes in tropical cyclone activity are among
the more potentially consequential results of global climate change, and
it is therefore of considerable interest to understand how
anthropogenic climate change may affect such storms. Global climate
models are currently used to estimate future climate change, but the
current generation of models lacks the horizontal resolution necessary
to resolve the intense inner core of tropical cyclones. Here we review a
new technique for inferring tropical cyclone climatology from the
output of global models, extend it to predict genesis climatologies
(rather than relying on historical climatology), and apply it to current
and future climate states simulated by a suite of global models
developed in support of the most recent Intergovernmental Panel on
Climate Change report. This new technique attacks the horizontal
resolution problem by using a specialized, coupled ocean–atmosphere
hurricane model phrased in angular momentum coordinates, which provide a
high resolution of the core at low cost. This model is run along each
of 2,000 storm tracks generated using an advection-and-beta model, which
is, in turn, driven by large-scale winds derived from the global
models. In an extension to this method, tracks are initiated by randomly
seeding large areas of the tropics with weak vortices and then allowing
the intensity model to determine their survival, based on large-scale
environmental conditions. We show that this method is largely successful
in reproducing the observed seasonal cycle and interannual variability
of tropical cyclones in the present climate, and that it is more
modestly successful in simulating their spatial distribution. When
applied to simulations of global climate with double the present
concentration of carbon dioxide, this method predicts substantial
changes and geographic shifts in tropical cyclone activity, but with
much variation among the global climate models used. Basinwide power
dissipation and storm intensity generally increase with global warming,
but the results vary from model to model and from basin to basin. Storm
frequency decreases in the Southern Hemisphere and north Indian Ocean,
increases in the western North Pacific, and is indeterminate elsewhere.
We demonstrate that in these simulations, the change in tropical cyclone
activity is greatly influenced by the increasing difference between the
moist entropy of the boundary layer and that of the middle troposphere
as the climate warms.” [14].

15. Professor Ross Garnaut (climate change economist and Australian Federal Government climate change adviser) warning that floods
and cyclones like those experienced by Australian in 2011 will get more
extreme as global warming increases (2011): “[while climate change
cannot be directly blamed for the recent flooding, or for Cyclone Yasi]
the greater energy in the atmosphere and the seas can intensify extreme
events and I'm afraid that we're feeling some of that today, and we're
feeling that at a time when global warming is in its early stages… [re
carbon tax and climate change action] "Getting back in the saddle, I
would like a result this time… We've taught ourselves that we're capable
of making quite a big mess of dealing with this diabolical policy
problem, I hope we've learnt something along the way…We haven't played
our proportionate part amongst developed countries so far. We've talked
about it from time to time, but we haven't done much…It will be quite
important for the international effort that Australia ceases to be a
drag on the international effort…I'm not talking about us leading the
world, I'm talking about our catching up." [15].

16. Parliament of Australia, Parliamentary Library
(that provides carefully researched infomation to members of the
Australian Federal Parliament) : “Are extreme weather events—severe
storms, flooding, droughts, heat waves or extremely violent
cyclones—becoming more common? The answer appears to be 'yes'. Trends
towards more powerful storms and hotter, longer dry periods have been
observed, according to the IPCC's Fourth Assessment Report, and this
trend is projected to continue.” [16].

17. Professor John Holdren (Professor
of Environmental Policy at the Kennedy School of Government at Harvard
University; Director of the Woods Hole Research Center; recent
Chairman of the American Association for the Advancement of Science and
President Obama’s chief scientific adviser) on climatic disruption
(2008): “Harm is
already occurring (continued). (Figure) Total power released by tropical
cyclones (green: Annual mean HADISST 30S-30N) has increased (circa
2-fold 1990-2003) along with sea surface temperatures (blue: West Pac +
East Pac + Atlantic); Kerry Emanuel, MIT, 2006”. [17].

18. Professor Vicky Pope
(head of climate change advice at the Met Office, UK) explains how a
warmer world is a wetter world (2011): "As the average global
temperature increases one would expect the moisture content of the
atmosphere to rise, due to more evaporation from the sea surface. For
every 1C sea surface temperature rise, atmospheric moisture over the
oceans increases by 6-8%. Also in general, as more energy and moisture
is put into the atmosphere [by warming], the likelihood of storms,
hurricanes and tornadoes increases." [18].

19. Dr Andrew Glikson
(former Principal Research Scientist, Australian Geological Survey
Organization, Earth and paleoclimate scientist. School of Archaeology
and Anthropology, Research School of Earth Science, Planetary Science
Institute, Australian National University) on Queensland floods [noting
according to the report, that climate scientists were careful never to
point to a single event as evidence of climate change but to examine
medium and long-term trends] : “'Cyclones have increased twofold over
the past 20 years. Floods have increased threefold. It's happening now,
and it's happening faster than some of the climate-change scientists
have dared to predict” [19].

20. William Cosgrove
(vice president, World Water Council), 3rd World Water Forum, 2003:
"Extreme weather records are [already] being broken every year and the
resulting hydro-meteorological disasters claim thousands of lives and
disrupt national economies," said of the Marseille-based think tank made
up of users and suppliers of water for social and economic development.
The big problem is that most countries aren't ready to deal adequately
with the severe natural disasters that we get now, a situation that will
become much worse as storms and droughts become more pervasive.
Ignoring the problem is no longer an option… The increasing incidence of
extreme events provides a convincing argument to continue looking into
building partnerships between science, water managers and the disaster
preparedness communities, including the development and dissemination of
capacity development packages and methodologies. It is telling that
disaster reduction has been recognized since 2000 an issue central to
poverty reduction. ” [20, 21].

21. World Water Council press
release from the 3rd World Water Forum re climate change, droughts and
floods (February 2003): “Economic loses from weather and flood
catastrophes have increased ten-fold over the past 50 years, partially
the result of rapid climate changes, the World Water Council (WWC) says.
These rapid climate changes are seen in more intense rainy seasons,
longer dry seasons, stronger storms, shifts in rainfall and rising sea
levels,. More disastrous floods and droughts have been the most visible
manifestations of these changes. From 1971 to 1995, floods affected more
than 1.5 billion people worldwide, or 100 million people per year,
according to experts. This total includes 318,000 killed, and more than
81 million left homeless. Major floods that left at least 1,000 people
dead and caused $1 billion in damages per episode have been the most
destructive… According to climate experts, the expected climatic change
during the 21st century will further intensify the hydrological cycle –
with rainy seasons becoming shorter and more intense in some regions,
while droughts in other areas will grow longer in duration, which could
endanger species and crops and lead to drops in food production
globally. Evidence for the link between climate change and increasing
climate variability is mounting rapidly. For example, scientific
research has linked the recent droughts in the USA and Afghanistan to
the effects of global warming… These climate disasters stemming from
climate variability include: Floods [and Droughts] - Based on data for
ther period 1950 to 1998, the number of major flood disasters has grown
considerably world-wide from decade to decade – six cases in the 1950s,
seven in the 1960s, eight in the 1970s, 18 in the 1980s, and 26 in the
1990s. The number of significant flood disasters in the 1990s was higher
than in the three previous decades combined. Overall, global
precipitation is estimated to have increased by about two percent since
1900, though not on a uniform basis. This disparity in new rainfall
caused some places to become wetter and others to get drier, such as
North Africa south of the Sahara. In the most calamitous storm surge,
the flood in Bangladesh in April 1991 killed 141,000 people. Two floods
in China, one in 1996 and the second in 1998, caused the highest
material losses of the decade, of the order of $30 billion and $26.5
billion, respectively. Floods also destroy the hard-won economic
advances that many in the developing world have accomplished, such as
the Mozambique floods of 2000, which left nearly 1 million homeless, and
Hurricane Mitch in Central America [1998]. Comparing the economic
impacts of the 2000 flood in Mozambique with the 2002 flood in Central
Europe clearly illustrates the disparity in how national economies are
impacted by extreme events. The cost of damages reflects the income
levels of the countries. According to officials at the World Bank, the
Mozambique flood resulted in a 45 percent drop in GDP in 2000, whereas
in Germany, the 2002 flood is estimated to have caused less than a one
percent drop in GDP…Hurricane Mitch [1998] killed 11,000 people, with
thousands of others missing. More than 3 million people were either
homeless or severely affected. In this extremely poor regions, estimates
of the total damage from the storm surpassed $5 billion. The President
of Honduras, Carlos Flores Facusse, claimed the storm destroyed 50 years
of progress. As far as the geographic distribution of the worst floods,
the majority occurred in Asian countries … In addition, the impact of
floods has had increasingly detrimental and disruptive effects on human
health. In flooded areas, some diseases such as diarrhea, which kills
2.2 million children under th4 age of five per year, or leptospirosis (a
systemic infection that can lead to meningitis and hemorrhagic
jaundice) spread more rapidly… Many countries in Africa have been
suffering from unprecedented droughts that may signal widespread climate
change … Sea level rise is a concern in coastal and low-lying areas,
including small islands. In addition to coastal flooding, saltwater
intrusion into freshwater aquifers present a threat to water supplies.
The average global sea level rise from 1900 to the year 2100 is expected
to be 0.48 meters (19 inches), between twice and four times the rate of
rise over the 20th century. The main effect on humans will be to
confront extreme events such as storm surges. Areas of greatest danger
include Small islands in the Pacific, mainly the Atolls; Coastal
low-lying countries like Bangladesh and the Netherlands; Coastal
mega-cities like Tokyo, Lagos, Buenos Aires and New York.” [20, 21].

22. Global Greenhouse Warming.com
on climate and floods: "Meteorologic floods are by far the most common
of the types of floods in the human experience, affecting parts of the
globe every year. Such floods can bring good, such as the fertile soils
formerly brought to the Nile Delta by annual flooding. However, large
floods are mostly known for their catastrophic loss of life and
property, such as in China and Bangladesh which repeatedly devastated by
floods - Bangladesh lost 300,000 people in November 1970 and more than
130,000 in April 1991, from cyclone-induced flooding, and the massive
flooding of the Yangtze River in China in 1931 caused more than 3
million deaths with a further 2 million in 1959 from flooding and
starvation. …By 2025, half the world's population will be living in
areas that are at risk from storms and other weather extremes," the
World Water Council said, citing evidence gathered by U.N. and other
experts. The economic cost of changes in climate and floods will be
huge, especially for poor countries that are likely to bear the brunt of
these events. The phrase Climate and Floods is something we will hear
more of in the years ahead.”[22].

23. Dr James Hansen
in “Storms of My Grandchildren” (2010): “Global warming does increase
the intensity of droughts and heat waves, and thus the area of forest
fires. However, because a warmer atmosphere holds more water vapour,
global warming must also increase the intensity of the other extreme of
the hydrological cycle – meaning heavier rains, more extreme floods, and
more intense storms driven by latent heat, including thunderstorms,
tornadoes, and tropical storms. I realized that I should have emphasized
more strongly [in his 1988 testimony to a US Senate Committee] that
both extremes increase with global warming.” [23].

24. American Association for the Advancement of Science (AAAS),
2006 (founded in 1848, AAAS serves some 262 affiliated societies and
academies of science, serving 10 million individuals; the AAAS journal
Science has the largest paid circulation of any peer-reviewed general
science journal in the world, with an estimated total readership of 1
million): “The scientific evidence is clear: global climate change
caused by human activities is occurring now, and it is a growing threat
to society. Accumulating data from across the globe reveal a wide array
of effects: rapidly melting glaciers, destabilization of major ice
sheets, increases in extreme weather, rising sea level, shifts in
species ranges, and more. The pace of change and the evidence of harm
have increased markedly over the last five years. The time to control
greenhouse gas emissions is now… In addition to rapidly reducing
greenhouse gas emissions, it is essential that we develop strategies to
adapt to ongoing changes and make communities more resilient to future
changes. The growing torrent of information presents a clear message: we
are already experiencing global climate change. It is time to muster
the political will for concerted action. Stronger leadership at all
levels is needed. The time is now. We must rise to the challenge. We owe
this to future generations.” [24].

25. Senator Christine Milne
(Australian Greens deputy leader; Tasmanian Greens senator) on man-made
climate change and Cyclone Yasi (2011): “This is a tragedy, but it is a
tragedy of climate change. The scientists have been saying that we are
going to experience more extreme weather events, that their intensity is
going to increase, their frequency.” [25]